Fluid-powered pump

ABSTRACT

A fluid-powered pump comprising four-way slide valves with fluid conduits connecting the slide valves in a closed circuit. Highand low-pressure fluid connections to the fluid conduits to cause the slide valves to actuate one another in series in a continuously repeating cycle within the closed circuit. The slide valves may be used to pump other fluids from low-pressure supply areas to high-pressure use areas, such as to pump liquid to the boiler in an absorption-type refrigeration system.

United States Patent Ralph B. Tllney Clayton, Mo.

Aug. 7. 1969 Aug. 3. 1971 Alco Controls Corporation St. Louis, Mo.

inventor Appl: No. Filed Patented Assignee FLUID-POWERED PUMP 5 Claims,2 Drawing Figs.

US. Cl.... 417/344 Int. Cl F04b 17/00 Field of Search 103/49;

References Cited UNITED STATES PATENTS 6/1960 Moeller et al 103/49FORElGN PATENTS 158,295 5/1953 Australia Primary Examiner-Robert M.Walker A!!0rney Kingsland, Rogers, Ezell, Eilers & Robbins ABSTRACT: Afluid-powered pump comprising four-way slide valves with fluid conduitsconnecting the slide valves in a I closed circuit. Highand low-pressurefluid connections to the fluid conduits to cause the slide valves toactuate one another in series in a continuously repeating cycle withinthe closed circuit. The slide valves may be used to pump other fluidsfrom low-pressure supply areas to high-pressure use areas, such as topump liquid to the boiler in an absorption-type refrigeration system.

FLUID-POWERED PUMP BRIEF DESCRIPTION OF THE INVENTION In thisfluid-powered pump, a closed circuit of four-way valves is provided.Preferably there are three valves. Each four-way valve has a slidingspool formed with lands on a stem. Fluid chambers are defined by groovesbetween adjacent lands within the confines of the housing. At the endsof the spool, there are pumping chambers through which another fluid maybe pumped as the spool reciprocates. A separate piston is reciprocativewithin each pumping chamber. One end of each piston contacts the spooland the other end of the piston is exposed to a port. Fluid conduitsconnected through the housing wall are alternately exposed to differentones of the fluid chambers that are defined by the grooves, dependingupon the position of the spool. The chambers in the spool ofa firstvalve are connected by these conduits to the ported ends of the pistonsof a second valve; the chambers of that second valve are connected bysimilar conduits to the ported ends of the pistons ofa third valve, andso forth. Finally, the chambers of the last valve are connected to theported ends of the pistons of the first valve to complete and close thecycle. In addition, the chambers defined by the grooves are individuallyconnected to sources of high and low-pressure fluids. By alternatelyporting these conduits between the chambers as the spools reciprocateand by maintaining the different chambers in constant communication withthe high and low-pressure fluid sources, the spools will reciprocate incontinuous succession. Thus, for a three-valve system, for example, whenthe first spool moves to one end, such as the left end of its housing,the spool of the second valve moves to the right and the spool of thethird valve moves to the left. When the spool of the third valve movesto the left, it moves the spool of the first valve to the right therebychanging the porting of fluid to move the spool of the second valve tothe left and thereafter cause movement of the third valve to the right.In this manner, reciprocation of the spools continues so long as thedifferent pressure fluids are supplied to the fluid chambers.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of thefluid-powered pump. FIG. 2 is a fragmentary schematic diagram of one endof a modified form of valve that may be incorporated in the pump.

DETAILED DESCRIPTION OF THE INVENTION This fluid-powered pump comprisesa plurality of fourway valves. In this description and in the drawing,three such valves 11, 12, and 13 are described and shown, but thefluidpowered pump will operate with two or more valves. The valves 11,12, and 13 are of identical construction.

Each valves 11, 12, and 13 has a valve body 15 that provides a slidechamber 16 and left and right end piston chambers 17 and 18. Thecross-sectional area of the slide chamber 16 is greater than that of thepiston chambers 17 and 18, although these relative dimensions my bevaried depending upon the desired relationship between pumping rate andpumping pressure, as will be described.

A spool or slide 19 is reciprocative within the slide chamber 16, Theslide 19 has a stem 20 and four lands 21, 22, 23, and 24. O-rings (notshown) or other suitable seals are provided between the lands 21, 22,23, and 24 and the inner wall of the slide chamber 16 so thatsubstantially no leakage occurs past any ofthese lands.

The volume within the housing 15 to the left of the land 21 constitutesa left end pumping chamber 26. The volume within the housing 15 to theright of the land 24 constitutes a right end pumping chamber 27. Thevolume within the housing 15 between the lands 21 and 22 constitutes alow-pressure return chamber 28. The volume within the housing 15 betweenthe lands 23 and 24 and surrounding the stem 20 constitutes anotherlow-pressure return chamber 29. The volume within the housing 15 betweenthe lands 22 and 23 and surrounding the stem 20 constitutes ahigh-pressure supply chamber 30.

A piston 32 is slidable within the piston chamber 17 and into the leftend pumping chamber 26. The piston has end faces 33 and 34 with one face34 bearing against the left end of the slide 19. Another piston 35 isslidable within the piston chamber 18 and into the right end pumpingchamber 27. The piston 35 has end faces 36 and 37 with one end face 36bearing against the right end of the slide 19.

A tube 42 that leads from a source (not shown) of highpressure powerfluid opens into the high-pressure supply chamber 30. Tubes 43 and 44that lead to low-pressure power fluid receivers (not shown) areconnected from the low-pressure return chambers 23 and 29. Thus, thechamber is always in constant communication with the high-pressure powerfluid source and the chambers 28 and 29 are always in constantcommunication with low-pressure power fluid returns.

Two tubes 45 and 46 lead from a source (not shown) of lowpressure fluidthat is to be pumped to an area (not shown) of higher pressure. Thislow-pressure fluid source may be the same as or different from thelow-pressure fluid source already mentioned. The area of higher pressureto which the pumped fluid is to be delivered is different from thehigh-pressure fluid source already mentioned. There are check valves 47and 48 respectively in the tubes 45 and 46, and the tubes 45 and 46 opento the respective pumping chambers 26 and 27. Other tubes 49 and 50 leadto the last-mentioned area (not shown) of higher pressure to which thelow-pressure fluid is to be pumped. The tubes 51 and 52 open from thepumping chambers 26 and 27, respectively. There are check valves 51 and52 in the tubes 49 and 50 respectively.

Since the four-way valve 12 and the four-way valve 13 are identical tothe four-way valve 11, they will not be described in detail. Theidentical parts of these valves have been given identical referencecharacters, with a single prime applied to the numbers for the valve 12and a double prime applied to the numbers ofthe valve 13.

There is a tube 56 that communicates with the slide chamber 16 of thevalve 11 and with the left end piston chamber 17 of the valve 12.Another tube 57 communicates with the slide chamber 16 of the valve 11and with the right end piston chamber 18 of the valve 12. When the slide19 of the valve 11 is in its extreme left-hand position, the tube 56communicates with the high-pressure power fluid supply chamber 30 andthe tube 57 communicates with the low-pressure power fluid returnchamber 29. As the slide 19 slides to the right, the piston 22 movespast the tube 56 to block communication between the tube 56 and thehigh-pressure power fluid supply chamber 30 and to thereafter establishcommunication between the tube 56 and the low-pressure power fluidreturn chamber 28. The piston 23 moves to block communication betweenthe tube 57 and the low-pressure power fluid return chamber 29 and tothereafter establish communication between the tube 57 and thehigh-pressure power fluid supply chamber 30.

A tube 58 communicates with the slide chamber 16 of the valve 12 andwith the left end piston chamber 17" of the valve 13. A similar tube 59communicates with the slide chamber 16' of the valve 12 and with theright end piston chamber 18" of the valve 13. When the slide 19' of thevalve 12 is in the leftmost position, the tube 58 communicates with thehighpressure power fluid supply chamber 30 and the tube 59 communicateswith the low-pressure power fluid return chamber 29'. When the slide 19is in the rightmost position, the tube 58 communicates with thelow-pressure power fluid return chamber 28 and the tube 59 communicateswith the highpressure power fluid supply chamber 30.

A tube 60 communicates with the slide chamber 16" of the valve 13 andwith the left end piston 17 of the valve 11. Another tube 61communicates with the slide chamber 16" of the valve 13 and with theright end piston chamber 18 of the valve 11. The tubes 60 and 61alternately communicate with the high-pressure power fluid supplychamber 30 and with the respective low-pressure power fluid returnchambers 28" and 29" as the slide 19" reciprocates between its left andright positions.

OPERATION High-pressure power fluid is continuously supplied to thehigh-pressure power fluid supply chamber 30 of the valve 11, to thehigh-pressure power fluid supply chamber 30' of the valve 12, and to thehigh-pressure power fluid supply chamber 30" of the valve 13. Thelow-pressure power fluid return chambers 28, 28', and 28" and 29, 29',and 29" of the valves 11, 12, and 13 are in constant communication withdemand areas for low-pressure power fluid through the respective tubes43, 43', and 43" and 44, 44, and 44". The tubes 47, 47', and 47" and 48,48, and 48" which communicate with the left and right pumping chambers26, 26', and 26' and 27, 27', and 27" of each of the three valves ll,12, and 13 are in constant communication with the source of low-pressurefluid to be pumped to a higher pressure area. The tubes 49, 49', and 49"and 50, 50', and 50" are in constant communication with the higherpressure area to which fluid is to be pumped.

When the slide 19 of the valve 1 1 moves to the left, communicationbetween the high-pressure power fluid supply chamber 30 and the tube 56is established and communication between the low-pressure power fluidreturn chamber 29 and the tube 57 is established. Hence, thehigh-pressure power fluid supplied through the tube 56 to the left endpiston chamber 17' of the valve 12 drives the piston 32', the slide 19,and the piston 35' of the valve 12 to the right. As the slide 19 isdriven to the right, it forces pumped fluid from the right end pumpingchamber 27 to the outlet tube 50, the check valve 48', preventing pumpedfluid from flowing back through the tube 46'. Likewise, pumped fluid isdrawn from the tube 45 into the left end pumping chamber 26. The checkvalve 51' prevents pumped fluid from flowing from the tube 49'.

As the slide 19 of the valve 12 is driven to the right, communicationbetween its high-pressure power fluid supply chamber 30' and the tube 59is established and communication between its low-pressure power fluidreturn chamber 28 and the tube 58 is established. Hence, the slide 19"of the valve 13 is driven to the left. As the slide 19" of the valve 13is driven to the left, communication is established between itshigh-pressure power fluid supply chamber 30" and the tube 60 andcommunication is established between its low-pressure power fluid returnchamber 29" and the tube 61. This supplies high-pressure power fluidthrough the tube 60 to the left end piston chamber 17 of the valve 11,driving the slide 19 of the valve 11 to be the right. With the'valveslide 19 of the valve 11 being driven to the right, reversal ofoperation of the valve 11, followed by reversal of operation of thevalve 12 and reversal of operation of the valve 13 takes place.

Thus, when the slide 19 of the valve 11 is driven to to the right, theporting of the tubes 56 and 57 to the high-pressure power fluid supplychamber 30 is reversed so the slide 19 of the valve 12 is now driven tothe left. As a result, the porting to the tubes 58 and 59 from thehigh-pressure power fluid supply chamber 30' of the valve 12 is reversedand the slide 19' of the valve 13-is driven to the right. When the slide19" is driven to the right, its porting to the tubes 60 and 61 is againreversed to again drive the slide 19 of the valve 11 to the left. Thus,as long as high-pressure power fluid is supplied to the tubes 42, 42',and 42" and the tubes 43, 43, and 43" and 44, 44', and 44" are connectedto low-pressure power fluid demand areas, the slides 19, 19', and 19"will continue to reciprocate, constantly pumping pumped fluid throughthe pumping chambers 26, 26', and 26" and 27, 27', and 27".

From the foregoing, it is apparent that in this fluid-powered pump, onepower fluid stream is used to pump another pumped fluid stream. Externalfluid seals are eliminated because the pump is a closed system. Thetroublesome seals that must be used to seal the shafts of motor-drivenpumps are not required in this fluid-powered ump. The pumping actionWIII start when power fluid is supp red regardless o the initialpositions of the slides, and will continue so long as the power fluidcontinues to be supplied.

In an absorption-type refrigeration-system, this pump may be used topump low-pressure liquid into the boiler or vapor generator against thehigh pressure existing in the vapor generator. Other fluids that mustflow against a high-pressure resistance may be pumped by thisfluid-powered pump.

The diameters of the pistons 32, 32', and 32" and 35, 35', and 35"relative to the diameters of the pistons on the slides 19, 19', and 19"may be varied to vary the pumping pressure and rate of flow of thepumped fluid. As the diameters of the pistons 32, 32 and 32" and 35,35', and 35 are increased, the pumping rates will be increased, but thepumping pressures will be decreased. FIG. 2 illustrates a modificationwherein A subscripts have been added to numerals which designate partssimilar to those shown in FIG. I. In FIG. 2, the piston 32A and itscounterpart at the other end of the valve 11A are of larger diameterthan the pistons 21A, 22A and the other pistons of the slide 19A. In thevalve of FIG. 2, the rate of flow of the pumped fluid is increased butthe pumping pressure is reduced.

I claim:

1. A fluid-powered pump comprising a first slide valve, a second slidevalve, and a third slide valve, each valve comprising: a housing with aslide reciprocative therein, a pumping chamber in each slide valve forcausing pumping of a fluid through the pumping chamber as the slide ofthe slide valve reciprocates, a conduit for delivering low-pressurefluid to each pumping chamber, a conduit for delivering fluid from thepumping chamber to a high-pressure receiver, means defining high andlow-pressure power fluid chambers in each slide valve, movable withmovements of theslide thereof, a highpressure power fluid source, alow-pressure power fluid return, means communicating the high-pressurepower fluid source to the high-pressure power fluid chamber, meanscommunicating the low-pressure power fluid return to the lowpressurepower fluid chamber, means to connect the valves in a closed cyclecomprising: conduit means for individually connecting the power fluidchambers of one slide valve with separate pressure-responsive portionsof the slide of another slide valve in a serial closedcircuit, means ineach valve to port the last-named conduit means to alternate connectionsthereof to the high and low-pressure power fluid chambers as the slidereciprocates, and means responsive to the said alternating ofconnections to cause closed circuit reciprocation of the slides andconsequent pumping of fluid through the pumping chambers.

2. The pump of claim 1 wherein the low-pressure power fluid chambercomprises a divided chamber with portions on opposite sides of the firstpower fluid chamber.

3. The pump of claim 1, wherein the cross-sectional areas of the pumpingchambers are smaller than the internal cross-sectional areas of theslide housings.

4. The pump of claim I wherein the cross-sectional areas of the pumpingchambers are greater than the internal cross-sectional areas of theslide housings.

5. The pump of claim 1 including a piston in each pumping chamberhavingone end bearing against the slide and the opposite end constituting asaid pressure-responsive portion.

1. A fluid-powered pump comprising a first slide valve, a second slidevalve, and a third slide valve, each valve comprising: a housing with aslide reciprocative therein, a pumping chamber in each slide valve forcausing pumping of a fluid through the pumping chamber as the slide ofthe slide valve reciprocates, a conduit for delivering low-pressurefluid to each pumping chamber, a conduit for delivering fluid from thepumping chamber to a high-pressure receiver, means defining high andlow-pressure power fluid chambers in each slide valve, movable withmovements of the slide thereof, a high-pressure power fluid source, alowpressure power fluid return, means communicating the highpressurepower fluid source to the high-pressure power fluid chamber, meanscommunicating the low-pressure power fluid return to the low-pressurepower fluid chamber, means to connect the valves in a closed cyclecomprising: conduit means for individually connecting the power fluidchambers of one slide valve with separate pressure-responsive portionsof the slide of another sliDe valve in a serial closed circuit, means ineach valve to port the last-named conduit means to alternate connectionsthereof to the high and low-pressure power fluid chambers as the slidereciprocates, and means responsive to the said alternating ofconnections to cause closed circuit reciprocation of the slides andconsequent pumping of fluid through the pumping chambers.
 2. The pump ofclaim 1 wherein the low-pressure power fluid chamber comprises a dividedchamber with portions on opposite sides of the first power fluidchamber.
 3. The pump of claim 1, wherein the cross-sectional areas ofthe pumping chambers are smaller than the internal cross-sectional areasof the slide housings.
 4. The pump of claim 1 wherein thecross-sectional areas of the pumping chambers are greater than theinternal cross-sectional areas of the slide housings.
 5. The pump ofclaim 1 including a piston in each pumping chamber having one endbearing against the slide and the opposite end constituting a saidpressure-responsive portion.